Dilatometric study of Ni2+xMn1-xGa under magnetic field

TL;DR

This paper investigates how applying a magnetic field induces large strains in Ni2+xMn1-xGa alloys during martensitic transformation, especially when structural and magnetic transitions coincide, using dilatometric and strain gage methods.

Contribution

It demonstrates the magnetic-field-induced strain behavior in Ni2+xMn1-xGa alloys and highlights the significance of coupled structural and magnetic transitions.

Findings

Large strain induced by magnetic field during martensitic transformation

Maximum strain observed when structural and magnetic transitions coincide

Magnetic field effects depend on alloy composition

Abstract

A study of polycrystalline and single crystalline Ni$_{2+x}$Mn$_{1-x}$Ga alloys by means of dilatometric and strain gage techniques shows that large strain can be induced in the temperature range of the martensitic transformation by application of an external magnetic field. The biggest strain induced by magnetic field was observed in the samples of chemical compositions where the structural and magnetic transitions couple, i.e. occur at the same temperature.